Note, this scale reads from right to left, the main scale is accurate to half a degree and the Vernier scale is read in minutes. Step A: The first line on the Vernier scale lines up a little bit past 155. Step B: The line on the Vernier scale that lines up best with the main scale is 15. Step C: The angle that’s opened up is 155° 15 .œ
EXERCISE 14.1VERNIER SCALE ON A SPECTROMETER Q1 What is the angle on the Vernier scale
shown in Fig 14.6? 0
10
Q2 What is the angle on the Vernier scale shown in Fig 14.7?
30 20 30 20 10 0
Fig 14.6
Fig 14.7
140
MANDATORY EXPERIMENT 19
Measurement of the Wavelength of Monochromatic Light Method 1: Using spectrometer
Procedure ■ Look through the eyepiece of the telescope to view the image of the light source directly opposite the collimator, i.e. the zero order image.
■ Rotate the telescope left until the first bright fringe is in focus in the centre of the cross threads.Note the reading of the angle (L) on the circular scale.
